Subnail pigmented nevus, that is, pigmented nevus is located on the nail bed (commonly known as the location of the finger (toe) nails), pigmented nevus is also referred to as nevus of color, spotted nevus or nevus, is a benign tumor of the skin most commonly seen in the skin composed of normal pigment-containing nevus cells, and is occasionally seen on the surface of the mucous membranes. There are various types of clinical manifestations. The color is mostly dark brown or black, and there are also colorless moles with no color. Nevus pigmentosus is a congenital benign tumor composed of pigment cells, most of which are benign; in the later stage, there are malignant changes; once the nevus pigmentosus becomes malignant, its malignant degree is extremely high, and metastasis is the fastest, and the treatment effect is not ideal. The disease can be seen in all parts of the skin, and the soles of the feet are the most common parts. The nevus of the junction nevus and the nevus with signs of malignant transformation should be removed in time. There are many types of nevus. Generally speaking, no treatment is needed. However, attention should be paid to the nevus on the metatarsal and nail beds, usually do not stimulate it casually and do not apply corrosive drugs indiscriminately, so as not to induce its malignant transformation. If the nevus increases rapidly in a short period of time, the color deepens and becomes black, the edge is red and irregular, the surface bleeds, breaks, and satellite-like damages appear in the surrounding area, it indicates that the nevus has malignant signs, and it should be surgically excised, and sent to the pathology for examination at the present time. Surgical methods generally include resection of the nail bed of the toenail, amputation of the toenail, and local excision flap transfer for repair, and we have treated many cases through the fibular flap of the bunion, and the reconstruction of the toenail has obtained good results.